Erosion has contributed to the exposure of eight sewer lines in the hillside leading from South Lakes Drive to Lake Audubon. If significant action is not taken, Reston could face serious environmental and public health situation.

That was the takeaway from a long discussion at Reston Association’s Board of Directors meeting Thursday, where the board passed several motions to commit money to study the issue and continue pressing Fairfax County officials to act on the issue.

“This is a health hazard waiting to happen,” said RA land use attorney John McBride, who warned that recent events in Flint, Mich., where a money-saving effort to change the water supply resulted in dangerous lead contamination.

Granted, Reston does not get its drinking water from Lake Audubon, but it is a popular recreational spot, and boaters, swimmers and pets who enter the lake could be severely affected.

“Any time you have public sewer lines and laterals in the air, you have problems,” said McBride. See more from him in this presentation.

At issue is stormwater runoff that starts at South Lakes High School and Langston Hughes Middle School, goes under South Lakes Drive and then through a steep drainage ditch running between Wakerobin Drive and Cedar Cover Cluster, emptying into Lake Audubon.

Years of runoff have contributed to significant erosion, which has left eight sewer pipes exposed, said Charles Smith of the Fairfax County Department of Public Works and Environmental Services.

Smith, speaking to the board Thursday, said the runoff area scored poorly in a scoping study done by the county last fall. The 49-acre area is 43-percent impervious surface (parking lots, roofs, turf athletic fields and other hard materials).

“Anything above 10 percent, streams start to unravel,” he said. “When you see a degraded stream and this amount of imperviousness, it is really not a surprise.”

Adding to the issue — a planned 40,000-square-foot addition for South Lakes High School. Fairfax County Public School officials said the addition does not have to follow updated environmental rules and is grandfathered in under older ones.

RA also will ask FCPS Superintendent Karen Garza and the Fairfax County Department of Public Works and Environmental Services to not approve the pending SLHS site plan “until a stable, non-erosive and adequate outfall is restored in the drainage channel.”

The board also authorized allocating up to $20,000 from its operating reserves fund to conduct an independent audit of the waterflow and mitigation measures and to use the results to research the validity of FCPS’ waiver of stormwater management/ best management practices.

School system officials were not present last night’s meeting. In a December letter to RA Board President Ellen Graves, Hynes said FCPS is proud of its commitment to environmental stewardship and adheres to best practices.

“In spite of FCPS’ commitment to environmental stewardship, the school system’s primary mission is to educate students countywide,” wrote Hynes. “…the school system must be very careful and purposeful in how capital funding is used. Regrettably, FCPS does not have the ability to either construct or fund initiatives which are not related specifically to that primary mission.”

However, money for remedies could be found in the county budget, which will work on Fiscal Year 2017 this spring, said Smith. If the county could include the issue for 2017, design and scoping work could begin this year and the project could be completed in three years, said Smith.

Most of the affected area is RA land, but some of it is on private homeowner property. If a fix takes place, it would require major land rights work to gain right-of-way on private property, said McBride.

However, it would be in residents’ best interest to allow it as they could be responsible for fixing breaks in the sewer line — as well as environmental cleanup — should they occur on their land, said McBride.

“What we need to do is to avoid Lake Audubon being a story on 60 Minutes,” said At-Large Director Ken Knueven. “We need to hold the supervisors accountable to create a mitigation team immediately. A pipe out in the open can break and cause a health situation.”

A situation was narrowly avoided in July, when a leak in an exposed pipe was discovered. It was fixed by the county, but not before 100 gallons of sewage spilled into Lake Audubon.

Terry Maynard, a Wakerobin resident and co-chair of the Reston 2020 Committee, says FCPS needs to find the money in its capital improvement budget for the fix.

“Given the slow growth in projected enrollment, I think it would be appropriate for the school board to divert up to one percent of that capital facilities budget –$4.7 million — to bring its stormwater management system at South Lakes High School in to compliance with current environmental law.

“I think our school system owes Reston this investment in its stormwater management to help prevent our ditch problem from becoming worse.”